ATI Fixture Problem....Ballast out?

[Eric81]

I have an 8 bulb 36" ATI Unit.....older unit, not the dimmable kind. I just noticed that my two center bulbs are out. Bulbs are only 3 months old, so I know it is not the bulb. Is there a ballast that controls those two that might be out?

Any ideas on what it is and how to fix it?

Thanks in advance!

 

[alan.reef]

try to swap the out bulb to the working one. if it light up either bad ballast or loose wiring possible.